Antibiotic
PREGNANCY RECOMMENDATION: No Human Data—Probably Compatible
BREASTFEEDING RECOMMENDATION: No Human Data—Probably Compatible
PREGNANCY SUMMARY
No reports describing the use of any of the three mupirocin formulations in human pregnancy have been located. The animal data and the minimal systemic concentrations in humans suggest that the embryo–fetal risk, if it exists at all, is probably nil.
FETAL RISK SUMMARY
Mupirocin is an antibacterial agent produced by fermentation from Pseudomonas fluorescens. It is active against many gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and some gram-negative bacteria. Mupirocin is bactericidal at concentrations achieved by topical application. Mupirocin cream is indicated for the treatment of secondarily infected traumatic skin lesions (up to 10 cm in length or 100 cm2 in area) due to susceptible strains of S. aureus and Streptococcus pyogenes. The ointment formulation is indicated for the topical treatment of impetigo due to S. aureus and S. pyogenes, whereas the nasal spray is indicated for the eradication of nasal colonization with MRSA in adult patients and health care workers (1).
Minimal amounts of mupirocin are absorbed into the systemic circulation after use of cream, but not after use of the ointment. For the nasal spray, the extrapolated systemic exposure, based on the concentration of the inactive metabolite monic acid in urine, was 3.3% of the dose. Any antibiotic reaching the circulation is rapidly metabolized to monic acid that is excreted in the urine. The elimination half-lives of mupirocin and monic acid after IV administration in healthy adults were 20–40 and 30–80 minutes, respectively (1).
Reproduction studies have been conducted in rats and rabbits. During pregnancy in these species, SC doses up to 78 and 154 times, respectively, the daily human topical dose of the cream based on BSA revealed no evidence of fetal harm. For the ointment, the dose comparisons were 22 and 43 times, respectively, the daily human topical dose based on BSA and, for the nasal spray, 65 and 130 times, respectively, the daily human intranasal dose based on BSA (1).
Studies for carcinogenicity have not been conducted with mupirocin. Multiple assays for mutagenicity were negative. SC doses in male and female rats revealed no evidence of impaired fertility or reproductive performance (1).
It is not known if mupirocin crosses the human placenta. The molecular weight of the free acid (about 501) is low enough for passage, but the minimal plasma concentrations and rapid metabolism and elimination suggest that clinically significant amounts of the antibiotic will not reach the embryo or the fetus.
BREASTFEEDING SUMMARY
No reports describing the use of mupirocin during human lactation have been located. The molecular weight of the free acid (about 501) is low enough for excretion into breast milk, but the minimal plasma concentrations and rapid metabolism and elimination suggest that clinically significant amounts of the antibiotic will not reach the milk.
Reference
1.Product information. Bactroban. GlaxoSmithKline, 2004.